Fluid meter



4Jurrie 9, 1936.

335 a-lm 2/ P. S. MORGAN FLUID METER Filed June 14, 1934 2 Sheets-Sheet1 Gttomeg June 9, 1936. P. s. MORGAN FLUID METER Filed June 14, 1954 2sheets-sheet 2 inventor Porer .j Morgan @Zia/ n Gttomeg Patented June 9,1936 UNITED STATES PATENT OFFICE FLUID METER Application June 14, 1934,Serial No. 730,597

2 Claims.

` 'Ihis invention relates to improvements in fluid meters of the typedisclosed in my copending application Serial No. 615,166, filed June 3,1932.

The invention contemplates the provision of a novel structural formationof a metering chamber to obtain the accurate fitting of a fabricatedstructure, with a View both to permit the possibilities of massproduction on an economical scale and to protect the parts fromoperating and assembling strains.

The invention also resides in an improved device for preventing leakageacross the metering elements in the form of a diaphragm controlledvalve.

These features, together with other structural improvements, are morespecifically set forth in the accompanying specification and drawings,wherein:

Fig. l is a vertical section through the metering device;

Fig. 2 is a section on the line 2-2 of Fig. 1; and Fig. 3 is a crosssection through a blade and shoe structure of an alternate type.

General structure I5 which encloses the upper plate I3 and the adjacentextremity of the member I0. The member I0 is formed with a radial angeI6 and it receives a gasket I1 which is engaged by the face I8 of theupper head. A second gasket I9 is interposed between the plate I3 andthe end vWall 2| of the portion I5.

Similarly, the lower plate 20 is received in a cylindrical portion 22 ofa lower head 23 and it abuts a shoulder 24 formed in the head, and thisjoint is sealed by a gasket 25. Theface 21 of the lower head engages agasket 28 which is mounted on a second fiange 29 formed on the memberI0.

The heads I4 and 23 are formed with aligned lugs 3I and 32 respectively,the former containing holes for receiving screws 33 and the lattercontaining tapped holes for receiving the tapped extremities of thescrews. Dowels 35, engaged in the heads and plates, and dowels 36,connectling the member I0 and the plates, serve to locate the parts forassembly.

It will be observed that when. the heads are drawn toward each other,the interposed plate `and cylinder structures are rmly clamped togetherby the pressure exerted through the gasket connections. This method ofconnecting the parts insures the clamping of the plates and cylinder,regardless of inequalities in the tensioning of the screws 33, and itfurthermore protects 5 these parts from distortion under suchconditions.

Rotor chamber 'Ihe inner wall 38 of the member III is roughly circularin shape and eccentric to the axis of this 1 member. `The plates I3'and20 cooperate to form a rotor chamber 39 within this member and they areformed with pairs of ports 4I and 42, and 43 and 44, respectively, whichpairs are similar, but disposed on opposite sides of the horizontal axisas viewed in Fig. 2. Each pair of ports together forms a segmentalopening divided by a spiral rib, herein indicated bythe numerals 45 and46, in the plates I3 and 20 respectively.

In a more specific aspect, it is preferred that 20 the wall 38 be formedto have a constant diameter at all angles of rotation. A wall of thischaracter may be constructed by forming dia- 4metrically opposedportions of equal arcs as radial portions, to provide a major arcuatesurface 25 41 and a minor arcuate surface 48 of a lesser radius, 'and byconnecting such surfaces with curved surfaces 49 and 5I, whichare formedas complementary harmonic curves of a type suitable both to provide fora constant rate of change of curvature and to 'retain the diametricalcharacteristics above referred to.

The rotor The rotor is formed of a spider 53 having a 35 plurality ofarms 54 which contain radial slots 55 adapted to receive rectilinearvanes or blades 56. The hub of the spiderv is formed with an axial holeinto which is pressed a spindle 51 having axle portions 58 and 59projecting therefrom 40 and received in bearings 6I and 62 formed in theplates I3 and. 28 respectively. I'he upper axle portion is formed with aslot 63 serving as a connection with a registering mechanism or thelike. The spider and spindle are drilled, as indicated -by the numerals60 and 64, to receive rods 65 which connect the opposed pairs of blades56. These rods and the blades are proportioned so that the sum of theirdiametrical dimensions nearly equals the diameter of the wall 38, and,as a result, when the rotor is rotated, the outer edges of the bladesare always retained in sliding contact with the wall 38.

In Fig. 3 there is shown a blade 61 which may, if desired, besubstituted for the described blade 55 56 where extreme accuracy ofcontact is required. The extremity of the blade 61 is formed with a slot68 which receives, with some clearance, a gib portion 69 of a. shoe 1|.The extremity of the shoe is formed with a curved head 12 for slidingengagement with the wall 38. Inasmuch as the pressures on one face ofthe vane are greater than on the opposite face, and there is acentrifugal force acting on the shoes, it follows that the shoe will beconstantly urged into contact with the wall 38, thereby preventingexcessive leakage between the various pockets formed by the vanes.

The upper and lower plates I3 and 20 are. each provided with asegmentalpocket, designated as 50 and 50a respectively, to receive anyliquid placed under pressure by the movement of the blades 56, therebypreventingv any tendency to bind during operation.

The upper head The upper head |4 contains an open input chamber 13,which is closed by the underlying plate I3, and a communicating radialfitting 14. which receives a supply pipe leading to a pump or othersource of liquid supply. It will be observed that the chamber is formedwith an angular end wall 15 whichinsures a smooth flow of liquid throughthe input ports 4| and 42, andl which additionally provides that anysubstantial air volume trapped in the rotor chamber may rise to a highpoint in the chamber 13 during inoperative periods. Communicatingdrilled holes 11 and 18 form an injector in the head I4, whereinairtrapped in the upper portion of the chamber 13 is drawn through thevertical hole 11, and thence through the ports 4| and 42 in a finelydivided state, in which condition it may be successfully carried withthe liquid stream through the output ports 43 and. 44.

The head |4 is also formed with a central hub 8|)r which engages theplate I3 in a leakproof fit through the provision of a gasket 19. Thishub contains an axial bearing 8| for receiving a driven shaft 82 of amechanism leading to any suitable device for registering the movement ofthe rotor.

Pressure equalizz'ng device The. lower head 23 is formed with an outletiitting 84, which receives the discharged liquid from the ports 43 and44 of the plate 20 and directs it into a discharge conduit 85. This headis also utilized to contain a device for obtaining theA equalization` ofpressures in the outlet conduit and certain portions of the meteringchamber, and it is formed with a chamber 86, located below the plate andseparated from the fitting 84 by a diametrically disposed gasket 81 andadividing wall 90. This chamberV communicates with portions of theoverlying rotor chamber 39 intermediate the pairs of ports thereofthrough holes 88 drilled in the plate 20. A second chamber 89 is formedin the face of the head 23, and it communicates with the chamber 86through a restricted passage 9| around the dowel. 35.

A diaphragm 92 of a flexible material, such as av gasoline-proof fabric,is secured across the openV face of the chamber 89 by a cap member 93and` screws 94. The cap member contains a chamber 95 which communicateswiththe outlet port 44 through drilled hoes 96, 91 in the memberY 93-and a communicatingtube 98 secured in the. fitting 84 of` thehead 23..It willthus be observed that the opposite sides of the diaphragm 92 arerespectively subjected to the pressure at the outlet and intermediateportions of the rotor chamber. Due to the restricted passage 9| into thechamber 89, the diaphragm is protected 5 against sudden movement, aswould be occasioned by throttling the discharge conduit, or othercauses.

A third chamber 99 is formed in the head 23, intermediate the chambers86 and 89, and it l0 communicates with the former through a valve seatIOI. A valve |92 engages the seat |0| and its stem I 03 projects axiallythrough a guide insert` |04 and to the diaphragm 92. The insert |94 isremovably retained in position by a gasket l5 I5 and a superimposed cap|06 secured to the head 23.

To protect the relatively fragile material of the diaphragm, it isreinforced on each face by a disc |01 and a washer ||0 which receive the20 shouldered extremity |08 of the valvestem |03 and which is secured inassembled relation byva nut |09. Upon the opening of the valve, bymovement of the diaphragm, liquid fromV the chamber 86 is introducedinto the chamber 99, 25 and thence it is directed` through a bleedconduit drilledv in the head 23 to an attached pipe H2, which isdirected in mostY instances to the suctionside of the supply pump'or toa supply reservoir.

The diaphragm 92 is assembled. under. such degree of tension and is sobalancedV that it has what might be termed a negative characteristic.That is to say, the unbalanced weightv of the diaphragm is such as tohold,lor, to tend' to 35 hold, the valve |02 at a very slight distance;from its seat 0 It has been found thatunder. comparatively slow rates offlow, the pressures. in thev chambers 8B and 89 approach very closely tothe pressure in the chamber 95, and thediier.- ential pressure might betoo small, inl absolute terms, to operate theA valve IOI. Accordingly,the diaphragm` 92 is givena slight'. bias tending to open the valve, sothat a very small differential pressure will produce the desired degreeof valve opening, without, however, alecting the accuracy when the flowis increased.

Operation The introduction of, liquid under pressure into the rotorchamber 39 through the ports 4|v and 42 causes the movement of the rotorin a counter-clockwise direction of rotation, with the pockets formed bythe vanes 56 first receiving a liquid load adjacent the ports 4l and.42, then 55 traversing the major arcuate portion 41 of the chamber, andfinally, due to the volume reducing eiect of the curved surface 49,discharging iuid through the ports 43 and 44?. During this operation, itwill be obvious that a considerable pressure drop will be createdbetween: the input and output portions of the device; to the eiect that,regardless of the mechanical perfection of the fitting of the blades tothe wall 38, leakage will take place through the pocketsbetween theports.

It will be apparent thatliquidV leaking into the pockets traversing,ythe arcuateV surfaces of the rotor Vchamber will raise theV pressure invsuch pockets, and concurrently cause. leakage to.. the' next pocketatthe outlet port. This latter leakage is prevented in the presentdevice by withdrawing the leakage or slippage'volumes from theintermediate pockets of the meter. This is accomplished by opposingthelpressuresin such pockets and the output side of the meter across thediaphragm 92, which will open the valve |02 and permit the drainage of asufficient volume of liquid from the intermediate pockets and throughthe bleed conduit l Il to equalize the pressures between these portionsof the metering device.

As a result, the conveyance of unmetered volumes of liquid between theinput and output ports will be prevented, and the device will reect theactual liquid passage on its registering instrumentalities, withoutrecourse to correcting devices which have hitherto been utilized. Y

It will thus be seen that in the present invention, there are providedvarious instrumentalities whereby an eiective and accurate meter may bemade at a low cost and which will maintain its effectiveness during longperiods of service. It will also be understood that while the presentimprovements have been illustrated in one embodiment only, they aresusceptible of other applications or modifications within the scope ofthe following claims.

I claim:

1. A fluid meter comprising a rotor chamber, upper and lower headmembers closing the ends of said chamber, a rotor disposed in saidchamber, an inlet port formed in said upper head for admitting iiuidtoone part of said chamber and rotor, a discharge port formed in saidlower head for receiving fluid from said chamber, said upper head beingformed adjacent said inlet port with a conduit spaced from and extendingtoward said chamber and a second conduit in communication with said rstnamed conduit, said second conduit extending toward said inlet port,whereby air entrapped in said head will be aspirated and dispersedthrough liquid passing through said chamber.

2. A fluid meter comprising a. rotor chamber, a. rotor in said chamber,upper and lower heads for said chamber to enclose the same, an inletport formed in the upper head, an outlet port formed in the lower headon the opposite side of said rotor, a pressure chamber, a diaphragmdisposed across said pressure chamber to divide the same into isolatedcompartments, a valve secured to said diaphragm, a draw-olf line iniluid communication with said valve, said valve being in fluidcommunication with one of said compartments, means for admitting fluidfrom said rotor chamber to one of said compartments, means for admittinguid from the discharge port of said lower head to the other of saidcompartments, said diaphragm being of such weight and under such tensionas to hold said valve slightly open when the pressure differential insaid compartments reaches a predetermined low value.

PORTER. S. MORGAN.

